Performance assessment of the single photon emission microscope: high spatial resolution SPECT imaging of small animal organs

Autor: J. Mejia, M.A. Reis, A.C.C. Miranda, I.R. Batista, M.R.F. Barboza, M.C. Shih, G. Fu, C.T. Chen, L.J. Meng, R.A. Bressan, E. Amaro Jr
Jazyk: angličtina
Rok vydání: 2013
Předmět:
Zdroj: Brazilian Journal of Medical and Biological Research, Vol 46, Iss 11, Pp 936-942 (2013)
Druh dokumentu: article
ISSN: 1414-431X
DOI: 10.1590/1414-431X20132764
Popis: The single photon emission microscope (SPEM) is an instrument developed to obtain high spatial resolution single photon emission computed tomography (SPECT) images of small structures inside the mouse brain. SPEM consists of two independent imaging devices, which combine a multipinhole collimator, a high-resolution, thallium-doped cesium iodide [CsI(Tl)] columnar scintillator, a demagnifying/intensifier tube, and an electron-multiplying charge-coupling device (CCD). Collimators have 300- and 450-µm diameter pinholes on tungsten slabs, in hexagonal arrays of 19 and 7 holes. Projection data are acquired in a photon-counting strategy, where CCD frames are stored at 50 frames per second, with a radius of rotation of 35 mm and magnification factor of one. The image reconstruction software tool is based on the maximum likelihood algorithm. Our aim was to evaluate the spatial resolution and sensitivity attainable with the seven-pinhole imaging device, together with the linearity for quantification on the tomographic images, and to test the instrument in obtaining tomographic images of different mouse organs. A spatial resolution better than 500 µm and a sensitivity of 21.6 counts·s-1·MBq-1 were reached, as well as a correlation coefficient between activity and intensity better than 0.99, when imaging 99mTc sources. Images of the thyroid, heart, lungs, and bones of mice were registered using 99mTc-labeled radiopharmaceuticals in times appropriate for routine preclinical experimentation of
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